[gdal-dev] gdal contour as transparent png/tif or svg/eps/pdf

[Robert Grah]

Hey there,

im trying to get a contour out of an GeoTiff file as transparent PNG or TIFF or even better as PDF/SVG or EPS file in my C++ program.
I found gdal_contour but was not able to get PDF driver running. 
How can I install more drivers to GDAL?

So my approach so far is like following:

gdal_contour -i 50 mygeotiff.tif contour
gdal_rasterize -burn 0 -l contour contour mygeotiff.tif

But with this I am not able to get a transparent contour.
Is there a different approach beside the command line utils to get contours in vectorformat or transparent png/tif out of the geoTiff?
It would be also great to add some anti-aliasing ;)...

Cheers,
Rob